Apparatus for cutting an unvulcanized viscoelastic mass

ABSTRACT

An unvulcanized viscoelastic mass is cut by a machine which applies tension at the line of cut. While applying tension at the line of cut, the machine also provides a means for maintaining the cut portions in spaced relationship and for continuously moving the mass into the cutting means. The apparatus is especially suitable for cutting silicone gum containing fillers, extenders, process aids and vulcanizing agents. The compounded gum is shipped to the ultimate consumer who vulcanizes the compounded gum to form silicone rubber. The rubber is used in high temperature automotive transmission gaskets, radiator hose, and fan belts.

United States Patent 1151 3,691,886

Elsworth 1451 Sept. 19, 1972 [54] APPARATUS FOR CUTTING AN 3,108,350/1963 Bergling ..25/ 108 UNVULCANIZED VISCOELASTIC 3,019,506 2/1962Pearne ..25/ 108 MASS 3,298,263 1/1967 Bigsby, Jr. et a1. ..83/41,383,133 6/1921 Lucke ..83/4 X [721 330 Albany- 2,692,328 10/1954 Jaye..264/128 x Shaker Road, Loudonville, NY. 13367 Primary Examiner-JamesM. Meister [22] Filed; Oct 30, 7 Attorney-Donald J. Vass, Donavon L.Favre, Frank L. Neuhauser, Oscar B. Waddell and Joseph B. For- [21]Appl. No.: 85,422 man 521 US. Cl. ..83/1, 83/175, 83/648, [571 ABSTRACT83/701 An unvulcanized viscoelastic mass is cut by a machine [51] Int.Cl. ..B26d 3/00 which applies tension at the line of cut. While apply-[58] Field of Search ..83/1, 4, 175, 701, 648; ing tension at th lin fut. the ma hin als pr /105,108,112,113,104;264/l38,139, vides a meansfor maintaining the cut portions in 157, 158; 18/2 J; 222/346, 30 spacedrelationship and for continuously moving the mass into the cuttingmeans. The apparatus is espe- 5 References Cited cially suitable forcutting silicone gum containing fillers, extenders, process aids andvulcanizing agents. UNITED STATES PATENTS The compounded gum is shippedto the ultimate consumer who vulcanizes the compounded gum to form if?silicone rubber. The rubber is used in high temperal628l 5/1927 3; er Jx ture automotive transmission gaskets, radiator hose,

s t e e e 1 u u e I I u f 2,941,253 6/1960 Jakobsson ..264/157 and belts1,920,982 8/1933 Hedrich ..25/ X 8 Claims, 10 Drawing Figures m J 21 1111 \\\)/))\L\ \'J 4 \(S I OOOOOO OQO OOOOOOOOOOOLO e fi r' 5A 22 2 9-? Zmmiinstmmz 3.691.886

SHEET 0F 5 in vent-arlPoberY'f/X [/SWarTh APPARATUS FOR CUTTING ANUNVULCANIZED VISCOELASTIC MASS BACKGROUND OF THE INVENTIONThis-invention relates to an apparatus for cutting an unvulcanizedviscoelastic mass.

Silicone rubber is made in much the same way that natural rubber andsynthetic rubber is made, i.e., by cross-linking a high molecular weightgum. The gum generally contains added materials such as fillers,extenders, pigments, process aids, vulcanizing agents and the like. Thegum containing these various additives is made by placing a mixture ofthe gum, filler, etc., into a doughmixer and thoroughly mixing thecomposition until it becomes completely homogeneous. This homogeneousproduct is called various things, such as R-gum (where the Rindicates'reinforced), compound (meaning the gum has been compoundedwith other materials), and gum base (meaning that the gum is now a basefor a finishing operation which converts it to silicone rubber). At thisstage of manufacture, the homogeneous material is an unvulcanizedviscoelastic mass having a Williams plasticity of at least 200 andpreferably having a Williams plasticity of from 300 to 800. The materialis very difficult to handle. When a portion is cut from a larger massand is allowed to again contact the larger mass it immediately adheresthereto and must be recut. If an attempt is made to cut the material asit leaves the doughmixer, it is in a heated condition and veryuncomfortable to handle. If an attempt is made to cut the material afterit is cooled, it is very stiff and difficult to cut. It is, however,necessary to cut the material in order that it may be placed in a filterpress which removes any dirt which may have been picked up in themanufacturing process up to this point.

In the normal batch process production of the vulcanizable siliconecompound, the material is first produced in a doughmixer, loaded into acart and transported to the filter press. The mass extending above thetop of the cart is removed and placed in the filter press and then thecontents of the cart are unloaded onto a conveyor by turning the cartupside down upon the conveyor belt; the cart removed and the unloadedcontents then automatically fed into the filter press. It is necessarythat the surface of the unvulcanized viscoelastic mass in the cart belevel so that a conveyor belt can be placed flat on the surface of themass and the conveyor belt secured to the cart. The cart attached to theconveyor belt is then inverted to unload the cart. The job of levellingthe top of the cart has normally been a tedious one performed by handand has taken as long as 20 man hours per cart.

SUMMARY OF THE INVENTION In accordance with the teaching of the presentinvention, the job of levelling the top of the cart filled with siliconecompound is accomplished by an apparatus which cuts the compound at aplane parallel to the top of the cart while applying tension at the lineof cut and holding the mass of compound which has been cut away from theremaindenof the compound. The cutting is accomplished by knife, a movingband or a piano wire which starts its line of cut at the front of thecart. After the cut is started, a transporter-separator also, at thesame time, moves the top portion of the cut material rearward to aconveyor belt thus preventing the top portion of the cut material fromrecontacting the mass in the cart and adhering thereto. The cutter, thetransporter-separator and the conveyor are positioned on a frame whichfits over and on both sides, of the cart. By the relative movement ofthe cart and the frame, the cutter moves into the compound contained inthe cart. It is immaterial whether the cart moves, the frame moves orthey both move simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view ofthe cart topper attached by a cable to a cart loaded with compound.

FIG. 2 is a perspective view of the cutting, transporter-separator andconveying portion of the topper.

FIG. 3 is a sectional side elevational view showing the relationship ofthe cutting and transporting portion, cutting the compound extendingabove the top surface of the cart, and the relation of the cutting andtransporter-separator to the cart.

FIG. 4 is a top plan sectional view of the cutting andtransporter-separator mechanism and its relation to the cart while thecompound is being cut.

FIG. 5 is a schematic diagram of the drive means for thetransporter-separator, conveyor and cable wind-up mechanism; and thecontrols for the drive means of the machine of the present invention.

FIG. 5A is a perspective elevational view of the drive means for thetransporter-separator, conveyor and cable wind-up mechanism.

FIG. 6 shows the cart after the compound extending above the cart hasbeen removed by the topper being brought to an unloading station.

FIG. 7 shows the conveyor system of the unloader station being broughtdown and placed upon the top of the cart.

FIG. 8 shows the cart and the conveyor system of the unloader stationbeing placed in the unloading position.

FIG. 9 shows the cart removed from the load and placed back on the floorwith the load left on the conveyor of the unloader station. 7

DESCRIPTION OF THE PREFERRED EMBODIMENTS As is shown by FIG. 1, cart 2is being drawn into topper 4 by cables 6. Cables 6 are terminated byhooks 7 which are attached to eyes 8. Eyes 8 are connected to cart 2 byremovable bracket 9. Bracket 9 fits into channel 9a on each side of thecart.

FIG. 2 shows the cutting transporter-separator and conveyor action whichoccurs when the cart reaches the topper. Here the compound 10 is cut byblade 12 and deflected upward by deflector 14. When the compound reachesteflon-coated transporter-separator 15, it is contacted by protrudingribs 18 which transports the compound to teflon-coated conveyor 20,while also exerting a lifting force causing tension and separation atthe line of cut of the compound.

As transporter-separator 15 which consists of a ribbed cylinder rotates,worm pulleys 22 and 24 which are mounted on the same shaft rotate at thesame rotational speed. As is best shown in FIG. 4, the pitch of thegrooves on worm pulley 24 is reversed from the pitch of the grooves onworm pulley 22 so that as the cable 6 is wound onto the worm pulleys itis wound from the outer ends of the worm pulleys toward the inner end.As worm pulleys 22 and 24 are smaller in diameter than the diameter oftransporter-separator 15, the speed at which the cart is drawn into thetopper 4 is less than the peripheral speed of the transporter-separator15.

As the cart moves into the cutter blade, the top of the load is removedby blade 12 carried by the transporterseparator and placed on conveyorbelt 20. When the operation is finished, the top surface of the compoundwithin the cart is level. The cart is removed from the topper. Thecompound on conveyor 20 is then conveyed into a ram extruder. The ramextruder forces the compound through a filter screen which removes anydirt which is present in the compound. The compound is then cut intoappropriate size pieces and shipped to the various silicone rubberfabricators who use the silicone compound for a large number of hightemperature applications including the manufacture of automotivetransmission gaskets, fan belts and radiator hose. Silicone rubberunlike conventional rubber does not harden and crack upon prolonged hightemperature usage.

The contents of the loaded cart are also fed into the same ram extruderand processed in the same manner. The cart is emptied by the use of anunloader station 26, shown in FIGS. 6, 7, 8 and 9. Cart 2 at the loweredge has a channel 28 on each side. The cart is brought to the unloadingstation and two forks 30 of the unloading station are inserted into thetwo channels 28 of the cart. A conveyor 32 rests upon two uprightmembers 34 and ispivotedly mounted upon two upright members 36. Theconveyor is then pivoted upon pivot point 38 and rotated l80which bringsit to the upper-surface of the cart. It is, of course, necessary thatthe top surface of the compoundin the cart be level. It is then attachedto the cart on both sides by two adjustable attachment members 40 whichare permanently pivotedly attached to the conveyor and detachablysecured to thecart. The forks 30 are attached to two arms .42 which arealso pivotedly mounted upon uprights 36 at the same pivot point asconveyor 32. As shown by FIG. 8, fork 30 and pivot arm 36 and conveyor32 are rotated in a clockwise. direction 180 resulting in the cart beingin an inverted position on the top of the conveyor 32 which is againresting upon uprights 34. The attaching means 40 are then removed fromthe cart and the forks 30 and pivot arms 36 are rotated in acounterclockwise direction 180 with the conveyor remaining in placeleaving the load on the conveyor and returning the cart to the floor.The load of silicone compound is then fed to the beforedescribed ramextruder and filter screen.

The cart 2 has wheels 44 and is free to roll into topper 4. Topper 4 haswheels 46 and is freeto roll in the opposite direction of the cart untilthe entire cart [with the exception of the rearward cable connectionbracket 9 has passed under cutter 12. During the operation ofthe'topper, it is immaterial whether the cart moves, the topper moves,on both move simultaneously.

The drive mechanism used in the topper is shown 8 basically in FIGS. and5A. The power source is air motor 47 which operates at 20,000 rpm. Gearboxes 48 and 49 are attached to the motor and reduce the speed to 3.5rpm. Sprocket 50 is attached to output shaft 51 of gear box 49 anddrives chain 52 which in turn drives Y sprocket 53. Sprocket 53 isattached to shaft 54 upon which is mounted both worm pulleys 22 and 24and transporter-separator 15. As best seen in FIG. 4, shaft 54 passesthrough bearing housings 56 where it is mounted and supported bybearings, not shown. The conveyor belt drive is best shown byperspective elevational view 5A. There motor driven sprocket 58 driveschain 60 which in turn drives sprocket 62. Sprocket 62 is mounted on acommon shaft 64 with sprocket 66 and causes sprocket 66 to turn, whichin turn drives chain 68, driving sprocket 70 which causes roller 72 toturn by the torque exerted through shaft 74. Roller 72 is covered withstrips of a typical commercially available grit filled high frictionanti-skid surface. Shaft 74 extends through brackets 78 and is supportedtherein by bearings, not shown. Conveyor belt 20 rides on a series offree rollers 82 and is driven by the rotation of shaft 74. These rollers82 are suspended by and rotate on internal nylon bearings,not shown. Thebearings are attached to shafts 84 which protrude through flange 86 andare prevented from moving there-through by collars 88. Collars 88 arelarger than i the holes in the flange through which shafts 84 protrude.Collars 88 are secured to shafts 84 by set screws, not shown. Rollers 82are smooth, steel rollers and are free to rotate onnylon bearings.

The controls for the air driven mechanism contained on the topper arebest shown by FIG. 5. The air enters pipe 90 and the admission of theair is controlled by air valve 92. The incoming air first passes throughair filter 94 and then passes through air oiler 96. Air conduit 90indicates the path the air takes in the normal forward operation of themachine. When air valve 98 is open the machine assumes its curringoperation. The air continues to pass through conduit 90 through shut-offvalve 100 past pressure gauge and into the forward inlet 112 of the airmotor. When the air is turned on. the motor continues in its forwardspeed until the wagon which is unloaded strikes shut-off valve 100. Thisshuts off the supply of air passing through conduit 90 and automaticallyturns off the motor upon the completion of the topping off of a cart.If, for any reason, it is desired to' run the motor in a forwarddirection after the auto-I matic shut-off valve has cut off the airsupply to the motor, this can be done by shut-off bypass valve 114 whichmerely provides a conduit around shut-off valve 100. When it is desiredto reverse the motor direction, air pressure is supplied to the motor inthe opposite direction. This is accomplished by taking an air supplyfrom the conduit 90 as it leaves the air oiler through conduit 116 toreverse valve 118. Conduit116 then provides the direction of the conduitused when the direction of air flow is reversed through the air motor.Conduit l 16 then provides the high pressure. air supply for air inlet120 of the air motor. This allows the air motor to be reversed for suchpurposes as unwinding 2,744,878-Srnith-Johannsen, 1956, U.S. Pat. No.

3,514,424-Noble et al., 1970, U.S. Pat. No. 3,017,378-Simpson, 1962,U.S. Pat. No. 3,464,945-- Martellock, 1969 and the prior art mentionedin the above-mentioned patents. The subsequent developments in thesilicone rubber art which are also well known are the silicone rubberscontaining fluorinated alkyl substituents and cyanoalkyl substituentswhich impart solvent resistance to the rubbers-The particular rubbersand compounds involved do not form a part of the present invention whichis directed to a means for cutting thevarious compounds.

EXAMPLE 1 A silicone compound was prepared by mixing a polysiloxane gum,filler, extender, pigment, process aid and a vulcanizing agent in adoughmixer. The product had a Williams plasticity of 275. This compoundwas dumped from the doughmixer into a cart and transported to thetopper. The cart was drawn into the topper and the compound extendingabove the top surface of the cart was removed by the topper. Thecompound which was removed was then loaded onto a conveyor and ramextruded through a filter 'screen. The cart was then unloaded onto theconveyor and the compound in the cart was ram extruded through a filterscreen.

EXAMPLE 2 Example l was repeated using a compound having a Williamsplasticity of 350.

EXAMPLE 3 Example 1 was repeated using a compound having a Williamsplasticity of 500.

EXAMPLE 4 Example 1 was repeated using a compound having a Williamsplasticity of 750.

EXAMPLE 5 Example 1 was repeated using a gum having a Williamsplasticity of 900.

The foregoing examples and specification have of necessity been directedto only a few of the many variables which are practicable in thepractice of the present invention. it should be understood, however,that many other variables are also within the scope of the presentinvention. The materials which can be cut include many others having aWilliams plasticity of at least 200 and are not limited to siliconesalthough silicone compound is preferred.

The height of the cut made into the compound contained in the cart canby minor obvious variations be changed. This can be accomplished byplacing hydraulie jacks between the wheels of the cart and the body ofthe cart and/or hydraulic jacks between the wheels of the topper and theframe of the topper so that the heights of either one or both may bevaried. Multiple cuts using various height machinery may also beaccomplished. The cutting means is not limited to the blade recited inthe examples but can include anyother cutting means well known in theart, including the afore-mentioned piano wire, moving band, and otherwell known cutting means.

Having thus described my invention, what I desire to secure by LettersPatent of the United States is:

1. An apparatus for cutting an unvulcamzed viscoelastic mass positionedin a cart capable of being rolled, said mass having a Williamsplasticity of at least 200 said apparatus having therein a frame, rollermeans on said frame such that frame is capable of moving horizontalcutting means mounted on the upper portion of said frame, horizontaldeflector means mounted on said frame adjacent to said cutting means, ahorizontal transporter-separator means having a shaft thereon andmounted on said frame adjacent to said elevational means and horizontalconveyor means mounted on said frame adjacent to saidtransporter-separator means comprising the improvement of worm gearmeans mounted on said shaft of said transporter-separator means andcable means connected to said worm gear means and having connectingmeans thereon such that cable means can be connected to said cart sothat said horizontal-separator means can simultaneously act on the cutviscoelastic mass as well as force said cutting means through saidviscoelastic mass through said worm gear means and said cable means.

2. The apparatus of claim 1 further characterized by the cutting meansbeing a wire.

3. The apparatus of claim 1 further characterized by the cutting meansbeing a band.

4. The apparatus of claim 1 further characterized by the cutting meansbeing a blade.

5. The apparatus of claim 1 further characterized by the material beingout having a Williams plasticity of from 300 to 800.

6. The apparatus of claim 1 further characterized by the material beingcut being a silicone compound having a Williams plasticity of from 300to 800.

7. The apparatus of claim 1 wherein said transporterseparator meanscomprises a cylinder having horizontal ribs thereon.

8. The apparatus of claim 1 wherein said cart has brackets thereon witheyes attached to said brackets and wherein said connecting means on saidcable means comprises hooks.

1. An apparatus for cutting an unvulcanized viscoelastic mass positionedin a cart capable of being rolled, said mass having a Williamsplasticity of at least 200 said apparatus having therein a frame, rollermeans on said frame such that frame is capable of moving horizontalcutting means mounted on the upper portion of said frame, horizontaldeflector means mounted on said frame adjacent to said cutting means, ahorizontal transporterseparator means having a shaft thereon and mountedon said frame adjacent to said elevational means and horizontal conveyormeans mounted on said frame adjacent to said transporter-separator meanscomprising the improvement of worm gear means mounted on said shaft ofsaid transporter-separator means and cable means connected to said wormgear means and having connecting means thereon such that cable means canbe connected to said cart so that said horizontal-separator means cansimultaneously act on the cut viscoelastic mass as well as force saidcutting means through said viscoelastic mass through said worm gearmeans and said cable means.
 2. The apparatus of claim 1 furthercharacterized by the cutting means being a wire.
 3. The apparatus ofclaim 1 further characterized by the cutting means being a band.
 4. Theapparatus of claim 1 further characterized by the cutting means being ablade.
 5. The apparatus of claim 1 further characterized by the materialbeing cut having a Williams plasticity of from 300 to
 800. 6. Theapparatus of claim 1 further characterized by the material being cutbeing a silicone compound having a Williams plasticity of from 300 to800.
 7. The apparatus of claim 1 wherein said transporter-separatormeans comprises a cylinder having horizontal ribs thereon.
 8. Theapparatus of claim 1 wherein said cart has brackets thereon with eyesattached to said brackets and wherein said connecting means on saidcable means comprises hooks.